We have to evaluate the fourth roots of unity.
For each natural number say 'n', there are exactly 'n' nth roots of unity which is expressed in the form as
where k=0,1,2,.... n-1
Since we have to evaluate the fourth root of unity.
Therefore, we take k=0,1,2,3 and n=4
So, we get
Now, For k=0, we get our first root as:
First root = 1
Now, for k=1, we get
(Eulers Formula)
So,
So, second root = i
Now, for k=2, we get
(Eulers Formula)
So,
Third root = -1
Now, for k=3, we get
(Eulers Formula)
So,
So, fourth root = -i
Hence, all the fourth roots of unity are 1, i, -1 and -i
Therefore, option D is correct as all the given roots in option A, B and C are the fourth roots of unity.
I will try to answer this question
The answer is D, because that is what you should get when you multiply it out.
4x^2 times x^2 = 4x^4 because...
1) multiply the 4 and the one in front of the x on the second term = 4 then
2) multiply x^2 times x^2 to get x^4, not x^3, so you can immediately eliminate A and B to save time.
Now let's deal with the second part..."may or may not be" part
A polynomial is an expression with more than two algebraic terms
terms are like...
2x + 3y ---there's two terms there, eventhough the 2 and x are multiplied, it doesn't count (same with the 3 and y)
since it only have two terms, not more than two terms, it is called a binomial, not polynomial. I think that's what they mean by that
one term with a variable (y,x,and so on) is called a monomial
one term with no var is called a constant
there's many more but hope this gave you some help
0.873175 rounded to the nearest hundredth is 0.87